From 75f3d9e320075027aa1348dea8a5da5085f9f47b Mon Sep 17 00:00:00 2001 From: MH Hung Date: Thu, 11 Sep 2025 11:05:11 +0800 Subject: [PATCH] feat(SortVowels): add C# solution --- .../2785-sort-vowels-in-a-string/README.md | 70 ++++++++++++ .../csharp/Program.cs | 108 ++++++++++++++++++ .../csharp/csharp.csproj | 10 ++ 3 files changed, 188 insertions(+) create mode 100644 problems/2785-sort-vowels-in-a-string/README.md create mode 100644 problems/2785-sort-vowels-in-a-string/csharp/Program.cs create mode 100644 problems/2785-sort-vowels-in-a-string/csharp/csharp.csproj diff --git a/problems/2785-sort-vowels-in-a-string/README.md b/problems/2785-sort-vowels-in-a-string/README.md new file mode 100644 index 0000000..54d3505 --- /dev/null +++ b/problems/2785-sort-vowels-in-a-string/README.md @@ -0,0 +1,70 @@ +# [2785] Sort Vowels In A String + +## 題目資訊 +- **難度**: Medium +- **標籤**: String, Sorting +- **題目連結**: [LeetCode](https://leetcode.com/problems/sort-vowels-in-a-string/) +- **練習日期**: 2025-09-11 + +## 題目描述 +給定一個 0-indexed 的字串 s，重新排列 s 以獲得新字串 t，使得： + +所有子音保持在原來的位置 +母音必須按照 ASCII 值的非遞減順序排序 + +更正式地說： + +如果存在索引 i，其中 0 <= i < s.length 且 s[i] 是子音，那麼 t[i] = s[i] +對於索引對 i, j，其中 0 <= i < j < s.length 且 s[i] 和 s[j] 都是母音，那麼 t[i] 的 ASCII 值不能高於 t[j] + +母音定義: 'a', 'e', 'i', 'o', 'u' 以及它們的大寫形式 + +## 解題思路 + +### 初步分析 +- 這題主要考察什麼概念？ + 這題主要考察字串處理和排序概念 +- 有什麼關鍵限制條件？ +- 預期時間/空間複雜度？ + O(n log k) / O(k)，其中 n 為字串長度，k 為母音數量 + +### 解法概述 +1. **解法**: + - 思路： + 1. 遍歷字串，收集所有母音及其位置 + 2. 對母音字符進行排序 + 3. 將排序後的母音按原位置重新放回字串 + - 時間複雜度：O(n + k log k) 其中 n 是字串長度，k 是母音數量 + - 空間複雜度：O(k) 存儲母音字符和位置 + +## 測試案例 + +### 範例輸入輸出 +``` +Input: s = "lEetcOde" +Output: "lEOtcede" +Explanation: +母音 'E', 'e', 'O', 'e' 排序後變成 'E', 'O', 'e', 'e' +``` + +### 邊界情況 +- `1 <= s.length <= 10^5` +- `s` consists only of letters of the English alphabet in uppercase and lowercase. + +## 學習筆記 + +### 今天學到什麼？ +- + +### 遇到的困難 +- + +### 改善方向 +- + +### 相關題目 +- [題目編號] 題目名稱 - 相似概念 +- [題目編號] 題目名稱 - 進階版本 + +--- +**總結**: 這題的核心概念是...，適合練習...技巧。 diff --git a/problems/2785-sort-vowels-in-a-string/csharp/Program.cs b/problems/2785-sort-vowels-in-a-string/csharp/Program.cs new file mode 100644 index 0000000..07b3032 --- /dev/null +++ b/problems/2785-sort-vowels-in-a-string/csharp/Program.cs @@ -0,0 +1,108 @@ +// LeetCode 2785: Sort Vowels In A String +// 難度: Medium +// 日期: 2025-09-11 + +using System; +using System.Collections.Generic; +using System.Linq; + +public class Solution { + public string SortVowels(string s) { + // to char[] + char[] sArray = s.ToCharArray(); + + // get all vowels + string vowels = "aeiouAEIOU"; + List vowelPositions = new List(); + List vowelChars = new List(); + + for(int i = 0; i < sArray.Length; i++){ + if(vowels.Contains(sArray[i])){ + vowelPositions.Add(i); + vowelChars.Add(sArray[i]); + } + } + + // sort all vowels + vowelChars.Sort(); + + // insert vowels + for(var i = 0; i < vowelPositions.Count; i++){ + sArray[vowelPositions[i]] = vowelChars[i]; + } + + return new string(sArray); + } +} + +// 測試程式 +public class Program { + public static void Main() { + Solution sol = new Solution(); + + // TODO: 加入測試案例 + TestCase1(sol); + TestCase2(sol); + TestCase3(sol); + TestCase4(sol); + TestCase5(sol); + TestCase6(sol); + TestCase7(sol); + } + + // 基本範例 - LeetCode官方例子 + static void TestCase1(Solution sol) { + var s = "lEetcOde"; + var result = sol.SortVowels(s); + var expected = "lEOtcede"; + Console.WriteLine($"Test 1: Input: \"{s}\", Result: \"{result}\", Expected: \"{expected}\", Pass: {result == expected}"); + } + + // 只有子音 - 沒有母音的情況 + static void TestCase2(Solution sol) { + var s = "lYmpH"; + var result = sol.SortVowels(s); + var expected = "lYmpH"; + Console.WriteLine($"Test 2: Input: \"{s}\", Result: \"{result}\", Expected: \"{expected}\", Pass: {result == expected}"); + } + + // 只有母音 - 測試排序功能 + static void TestCase3(Solution sol) { + var s = "aEiOu"; + var result = sol.SortVowels(s); + var expected = "EOaiu"; + Console.WriteLine($"Test 3: Input: \"{s}\", Result: \"{result}\", Expected: \"{expected}\", Pass: {result == expected}"); + } + + // 混合大小寫母音 + static void TestCase4(Solution sol) { + var s = "TestcasE"; + var result = sol.SortVowels(s); + var expected = "TEstcase"; + Console.WriteLine($"Test 4: Input: \"{s}\", Result: \"{result}\", Expected: \"{expected}\", Pass: {result == expected}"); + } + + // 單一字元 - 邊界情況 + static void TestCase5(Solution sol) { + var s = "a"; + var result = sol.SortVowels(s); + var expected = "a"; + Console.WriteLine($"Test 5: Input: \"{s}\", Result: \"{result}\", Expected: \"{expected}\", Pass: {result == expected}"); + } + + // 重複母音 + static void TestCase6(Solution sol) { + var s = "Aa"; + var result = sol.SortVowels(s); + var expected = "Aa"; + Console.WriteLine($"Test 6: Input: \"{s}\", Result: \"{result}\", Expected: \"{expected}\", Pass: {result == expected}"); + } + + // 較長的字串測試 + static void TestCase7(Solution sol) { + var s = "RaInBoW"; + var result = sol.SortVowels(s); + var expected = "RIanBoW"; + Console.WriteLine($"Test 7: Input: \"{s}\", Result: \"{result}\", Expected: \"{expected}\", Pass: {result == expected}"); + } +} diff --git a/problems/2785-sort-vowels-in-a-string/csharp/csharp.csproj b/problems/2785-sort-vowels-in-a-string/csharp/csharp.csproj new file mode 100644 index 0000000..2150e37 --- /dev/null +++ b/problems/2785-sort-vowels-in-a-string/csharp/csharp.csproj @@ -0,0 +1,10 @@ + + + + Exe + net8.0 + enable + enable + + +